聚合氯化铝对A-BAF工艺运行特性的影响

为解决曝气生物滤池(biological aerated filter,BAF)工艺不能有效除磷的问题,采用向缺氧-曝气生物滤池工艺(anoxic-biological aerated filter,A-BAF)缺氧段投加聚合氯化铝的方法以提高除磷效果.通过小试试验考察聚合氯化铝(poly aluminum chloride,PAC)对A-BAF工艺运行特性的影响.结果表明:投加PAC能有效提高A-BAF工艺的除磷效果,对有机物的去除、硝化和反硝化均无明显影响.在进水TP为3.5 mg/L、PAC投加量为100 mg/L的条件下,出水TP由2.57 mg/L降至0.34 mg/L;而出水COD、NH4+-N和TN质量浓度均在30、1和11 mg/L左右.同时,投加PAC有利于延长BAF滤柱的反冲洗周期,反冲洗周期由原来的4 d提高到10 d,剩余污泥的比阻也由未投加药剂时的210×1012m/kg降至125×1012m/kg.

Effect of PAC on the operation characteristics of A-BAF

To overcome the shortcoming of biological aerated filter(BAF) on phosphorus removal,poly aluminum chloride(PAC) was dosed into the anoxic tank of anoxic-biological aerated filter(A-BAF).The effects of PAC on the phosphorus,organic matter and nitrogen removal by A-BAF and the head-loss development of BAF were investigated through a lab-scale experiment.The results showed that the addition of PAC had a positive effect on phosphorus removal by A-BAF,but had no effect on the removal of organic matter and nitrogen.With the PAC dosage of 100 mg/L,the TP concentration in effluent was reduced from 2.57 mg/L to 0.34 mg/L,when the influent TP concentration was 3.5 mg/L.The COD,NH+4-N and TN concentration in effluent were 30,1 and 11 mg/L separately,which were similar to those in the effluent without PAC.Meanwhile,the backwashing cycle of BAF was increased from 4 d to 10 d and the specific resistance to filtration of the excess sludge was decreased from 210×1012m/kg to 125×1012m/kg after PAC dosing.